| Device | Sensing | Feedback | Known result | What TEK does differently |
|---|---|---|---|---|
| van Erp waist belt (2005) | none, waypoints from navigation | 8 waist tactors | direction coding needs no training; rhythm for distance did not help | live distance sensing, distance by amplitude |
| A commercial compass belt | compass | 16 belt ERMs | seven weeks, 11 blind users, less discomfort and more confidence; reimbursed by German insurers | obstacles and drop offs, not north |
| A wrist sonar band | wrist sonar | wrist haptic | up to about 5.5 m, single channel, discontinued | full body 20 channel map |
| A clip-on sonar | clip sonar | single vibration | discontinued; a robotic aid beat it on collisions | 20 channel spatial map |
| A smart mobility aid handle | mobility aid handle sonar plus app | handle haptic and audio | not published | hands free, body worn, far cheaper |
| A GPS route app | GPS | audio | route guidance, not obstacles | hazard reflex, not turn by turn |
THE ENGINEERING RECORD, FILE 16 OF 19
Prior art comparison
Source: docs/16-prior-art.md, the engineering record. Every number on this page is read from that file. If a fact is not in the record, it is measured on the bench, or it stays off this site.